An investigation of relationship between shape constancy and introversion‐extroversion was carried out, using as subjects twenty‐four first‐year Psychology students of Aberdeen University; twelve introverts and twelve extroverts, selected on basis of Minnesota TSE scale. Results showed ( a ) that introverts showed lower constancy effect than extroverts and ( b ) that there was a tendency for men to show greater constancy effect than women. There was also some suggestion of presence of a learning factor in perceptual process which also distinguished introverts from extroverts. These results are discussed in light of previous investigations. Hypotheses, which are shortly to be tested, and which might account for findings, are advanced.